Field of the Disclosure
The present disclosure relates to an organic compound, an electrochromic compound, and an electrochromic element, an optical filter, a lens unit, an imaging device, and a window component having the same.
Description of the Related Art
An electrochromic element (EC element) is an element having a pair of electrodes and an electrochromic layer (EC layer) disposed between the pair of electrodes. By applying a voltage to the pair of electrodes, the amount of light passing through an EC layer can be adjusted.
For such an EC element, an electrochromic compound (EC compound) having an electrochromic property (EC property) has been used in which the optical absorption properties (coloration state and light transmittance) of a substance change clue to reversible progress of an electrochemical redox reaction. Examples of low molecular weight organic EC compounds include a viologen derivative which is a cathodic EC compound colored by reduction, a phenazine derivative which is an anodic EC compound colored by oxidation, and the like.
The EC element has been applied to a light control mirror of automobiles, electronic paper, and the like using the EC compounds. The devices utilize the property that the display of various color tones can be achieved by selecting the EC compound. In utilizing the EC element, a development of materials of various color tones has suggested the possibility of wide use thereof.
Japanese Patent Laid-Open No. 61-148162 describes a viologen derivative in which an alkyl group is introduced into carbon atoms of at least one of two pyridyl groups forming 4,4′-bipyridinium. Japanese Patent Laid-open No. 61-148162 describes a viologen derivative in which alkyl groups are bonded to the 2,2′ sites of the 4,4′-bipyridinium and a viologen derivative in which alkyl groups are bonded to the 3,3′ sites of the 4,4′-bipyridinium as specific examples.
However, the wavelength of the absorption peak in a colored state of the viologen derivative in which alkyl groups are bonded to the 2,2′ sites of 4,4′-bipyridinium described in Japanese Patent Laid-Open No. 61-148162 has been almost the same as that of viologen not having a substituent in carbon atoms of 4,4′-bipyridinium. In the viologen derivative in which alkyl groups are bonded to the 3,3′ sites of 4,4′-bipyridinium, the wavelength of the absorption peak appears in a long wavelength band but the redox reaction does not reversibly progress, and the derivative does not have the EC property.